Android Open Source - opengl Cube Small G L U T

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License

The source code is released under:

Apache License

Java Source Code

package com.androidbook.opengl;
//w w  w .ja  v  a 2 s .  co  m
import java.nio.ByteBuffer;
import java.nio.FloatBuffer;

import javax.microedition.khronos.opengles.GL10;

public class CubeSmallGLUT extends SmallGLUT {

    private float mSize;
    
    private FloatBuffer mVertexBuffer;
    private FloatBuffer mNormalBuffer;
    private ByteBuffer mIndexBuffer;
    
    CubeSmallGLUT(float size) throws IllegalArgumentException {
  if (size < 0.0f) {
      throw new IllegalArgumentException("Only use positive size values to CubeSmallGLUT");
  }
  // scale unit cube to this size
  mSize = size;
  
  if (mSize != 1.0f) {
      for (int vertex = 0; vertex < vertices.length; vertex++ ) {
    vertices[vertex] *= mSize;
      }
  }
  
  mVertexBuffer = getFloatBufferFromFloatArray(vertices);
  mNormalBuffer = getFloatBufferFromFloatArray(normals);
  mIndexBuffer = getByteBufferFromByteArray(indices);
    }
    
    // center our unit cube around the origin so translations make sense
    float vertices[] = {
      // front
      -0.5f, 0.5f, 0.5f,   0.5f, 0.5f, 0.5f,   0.5f,-0.5f, 0.5f,  -0.5f,-0.5f, 0.5f,
      
      // back
       0.5f, 0.5f,-0.5f,  -0.5f, 0.5f,-0.5f,  -0.5f,-0.5f,-0.5f,   0.5f,-0.5f,-0.5f,
      
      // top
      -0.5f, 0.5f,-0.5f,   0.5f, 0.5f,-0.5f,   0.5f, 0.5f, 0.5f,  -0.5f, 0.5f, 0.5f,
      
      // bottom
      -0.5f,-0.5f, 0.5f,   0.5f,-0.5f, 0.5f,   0.5f,-0.5f,-0.5f,  -0.5f,-0.5f,-0.5f,
      
      // right
       0.5f, 0.5f, 0.5f,   0.5f, 0.5f,-0.5f,   0.5f,-0.5f,-0.5f,   0.5f,-0.5f, 0.5f,
       
      // left
      -0.5f, 0.5f,-0.5f, -0.5f, 0.5f, 0.5f,  -0.5f,-0.5f, 0.5f,  -0.5f,-0.5f,-0.5f,
    };
    
    byte indices[] = {
      //front
      0,1,2, 2,3,0,
      //back
      4,5,6, 6,7,4,
      // top
      8,9,10, 10,11,8,
      // bottom
      12,13,14,  14,15,12,
      //right
      16,17,18,  18,19,16,
      //left
      20,21,22,  22,23,20,
    };
    
    float normals[] = {
    // front
            0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1,
            // back
            0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1,
            // top
            0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0,
            // bottom
            0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0,
            // right
            1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0,
            // left
            -1, 0, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, };
    
    
    void draw(GL10 gl) {
  // need for correct culling
  gl.glFrontFace(GL10.GL_CW);
         
  // make sure our state is correct
        gl.glEnableClientState(GL10.GL_NORMAL_ARRAY);

        // set our vertexes
        gl.glVertexPointer(3, GL10.GL_FLOAT, 0, mVertexBuffer);

        // set our normals for correct lighting
        gl.glNormalPointer(GL10.GL_FLOAT, 0, mNormalBuffer);

        // draw the elements
        gl.glDrawElements(GL10.GL_TRIANGLES, indices.length,
                GL10.GL_UNSIGNED_BYTE, mIndexBuffer);
  
  // GLUT disables the client state -- we don't. Why does it? .. 
  // TODO: consider a preDraw, draw, postDraw ...
  
    }
    
    void drawAgain(GL10 gl) {
  // used to draw again when the vertex and normal pointers haven't changed -- won't work otherwise

  // draw the elements -- assuming all of the above prep has taken place
  gl.glDrawElements(GL10.GL_TRIANGLES, indices.length, GL10.GL_UNSIGNED_BYTE, mIndexBuffer);
    }
    
    void drawSimpleCube (GL10 gl) {
        float vertices[] = {
                -1,1,1, 1,1,1, 1,-1,1, -1,-1,1,
                1,1,-1, -1,1,-1, -1,-1,-1, 1,-1,-1
        };
        byte indices[] = {
                0,1,2, 2,3,0,  1,4,7, 7,2,1,  0,3,6, 6,5,0,
                3,2,7, 7,6,3,  0,1,4, 4,5,0,  5,6,7, 7,4,5
        };
        FloatBuffer vertexBuffer = getFloatBufferFromFloatArray(vertices);
        ByteBuffer indexBuffer = getByteBufferFromByteArray(indices);
        gl.glVertexPointer(3, GL10.GL_FLOAT, 0, vertexBuffer);
        gl.glDrawElements(GL10.GL_TRIANGLES, indices.length, GL10.GL_UNSIGNED_BYTE, indexBuffer);
        //gl.glDrawElements(GL10.GL_LINE_LOOP, indices.length, GL10.GL_UNSIGNED_BYTE, indexBuffer);
        
    }
   
    
}

Java Source Code List

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